Facebook just pushed out an update to its iOS app. Facebook for iOS 5.0.1 includes iOS 6 and iPhone 5 support. Here's more info:

What's New in Version 5.0.1:

* Scrolling through news feed is faster than ever* New banner lets you tap to quickly see more stories - no need to refresh* Photos open fast and close with one downward swipe* Instant access to your notifications* (5.0.1) Support for iOS 6 and iPhone 5; bug fixes